First report of causing root rot on in China.

Soil-borne plant-pathogenic spp. can cause root rot and damping off on important plant species, resulting in serious economic loss. A survey in October 2021 identified soil-borne diseases occurring on in Yunnan Province, China.

[Difference of rhizosphere microbe quantity and functional diversity among three flue-cured tobacco cultivars with different resistance].

Field experiments were conducted in Shilin and Xundian respectively to study the diffe- rence of rhizosphere microbe quantity and functional diversity with plate culture method and Biolog technique among Hongda (high susceptibility, S), Yun87 (middle resistance, MR) and K326 (high resistance, R) , three flue-cured tobacco cultivars with different resistance to bacterial wilt and black shank. The results indicated that the amounts of bacteria, actinomycetes and the total number of microbes in tobacco plants' rhizosphere were positively correlated with the cultivar' s re- sistance, while it was opposite for the fungi. The consistent tendency was obtained not only at 35 d, 55 d and 75 d after transplanting, but also at two experimental sites.

[Nutrient balance between N, P, and K in flue-cured tobacco production under different preceding crops planting].

A field experiment was conducted to study the nutrient balance between N, P, and K in flue-cured tobacco production in Shilin County of Yunnan Province under the effects of different preceding crops including rape, wheat, barley, and green manure planting. Overall, there existed significant differences in the soil nitrogen availability, tobacco plant dry matter accumulation, plant uptake of N, P and K, residual amounts of soil N, P, and K, apparent soil N loss, and apparent soil P- and K surplus during tobacco growth period under different preceding crops planting. Under preceding crop green mature planting, the soil mineral N content before tobacco plant transplanting, the soil N net mineralization rate during tobacco growth period, and the tobacco plant dry matter accumulation and N- and K uptake at maturation were all the highest, followed by under preceding rape planting, and under preceding barley or wheat planting.